void RTMFP::Encode(RTMFPEngine& aesEncrypt,PacketWriter& packet) {
// paddingBytesLength=(0xffffffff-plainRequestLength+5)&0x0F
int paddingBytesLength = (0xFFFFFFFF-packet.size()+5)&0x0F;
// Padd the plain request with paddingBytesLength of value 0xff at the end
while (paddingBytesLength-->0)
packet.write8(0xFF);
WriteCRC(packet);
// Encrypt the resulted request
aesEncrypt.process(packet.data()+4,(UInt8*)packet.data()+4,packet.size()-4);
}
void Handshake::createCookie(PacketWriter& writer,HelloAttempt& attempt,const string& tag,const string& queryUrl) {
// New Cookie
Cookie* pCookie = attempt.pCookie;
if(!pCookie) {
if(attempt.pTarget)
pCookie = new Cookie(*this,invoker,tag,*attempt.pTarget);
else
pCookie = new Cookie(*this,invoker,tag,queryUrl);
_cookies[pCookie->value()] = pCookie;
attempt.pCookie = pCookie;
}
writer.write8(COOKIE_SIZE);
writer.writeRaw(pCookie->value(),COOKIE_SIZE);
}
void FlowWriter::flush(PacketWriter& writer,UInt64 stage,UInt8 flags,bool header,BinaryReader& reader,UInt16 size) {
if(_stageAck==0 && header)
flags |= MESSAGE_HEADER;
if(size==0)
flags |= MESSAGE_ABANDONMENT;
if(_closed && _messages.size()==1) // On LAST message
flags |= MESSAGE_END;
// TRACE("FlowWriter %u stage %u",id,stage);
writer.write8(flags);
if(header) {
writer.write7BitLongValue(id);
writer.write7BitLongValue(stage);
writer.write7BitLongValue(stage-_stageAck);
// signature
if(_stageAck==0) {
writer.writeString8(signature);
// No write this in the case where it's a new flow!
if(flowId>0) {
writer.write8(1+Util::Get7BitValueSize(flowId)); // following size
writer.write8(0x0a); // Unknown!
writer.write7BitLongValue(flowId);
}
writer.write8(0); // marker of end for this part
}
}
if(size>0) {
reader.readRaw(writer.begin()+writer.position(),size);
writer.next(size);
}
}
// TODO make perhaps a FlowHandshake
UInt8 Handshake::handshakeHandler(UInt8 id,PacketReader& request,PacketWriter& response) {
switch(id){
case 0x30: {
request.read8(); // passer un caractere (boite dans boite)
UInt8 epdLen = request.read8()-1;
UInt8 type = request.read8();
string epd;
request.readRaw(epdLen,epd);
string tag;
request.readRaw(16,tag);
response.writeString8(tag);
// UDP hole punching
if(type == 0x0f)
return _gateway.p2pHandshake(tag,response,peer().address,(const UInt8*)epd.c_str());
if(type == 0x0a){
/// Handshake
// RESPONSE 38
// New Cookie
char cookie[65];
RandomInputStream ris;
ris.read(cookie,64);
cookie[64]='\0';
response.write8(64);
response.writeRaw(cookie,64);
_cookies[cookie] = new Cookie(epd);
// instance id (certificat in the middle)
response.writeRaw(_certificat,sizeof(_certificat));
return 0x70;
} else {
ERROR("Unkown handshake first way with '%02x' type",type);
}
break;
}
case 0x38: {
_farId = request.read32();
string cookie;
request.readRaw(request.read8(),cookie);
map<string,Cookie*>::iterator itCookie = _cookies.find(cookie.c_str());
if(itCookie==_cookies.end()) {
ERROR("Handshake cookie '%s' unknown",cookie.c_str());
return 0;
}
request.read8(); // why 0x81?
// signature
string farSignature;
request.readString8(farSignature); // 81 02 1D 02 stable
// farPubKeyPart
UInt8 farPubKeyPart[128];
request.readRaw((char*)farPubKeyPart,sizeof(farPubKeyPart));
string farCertificat;
request.readString8(farCertificat);
// peerId = SHA256(farSignature+farPubKey)
string temp(farSignature);
temp.append((char*)farPubKeyPart,sizeof(farPubKeyPart));
EVP_Digest(temp.c_str(),temp.size(),(UInt8*)peer().id,NULL,EVP_sha256(),NULL);
// Compute Diffie-Hellman secret
UInt8 pubKey[128];
UInt8 sharedSecret[128];
RTMFP::EndDiffieHellman(RTMFP::BeginDiffieHellman(pubKey),farPubKeyPart,sharedSecret);
// Compute Keys
UInt8 requestKey[AES_KEY_SIZE];
UInt8 responseKey[AES_KEY_SIZE];
RTMFP::ComputeAsymetricKeys(sharedSecret,pubKey,_signature,farCertificat,requestKey,responseKey);
// RESPONSE
Util::UnpackUrl(itCookie->second->queryUrl,(string&)peer().path,(map<string,string>&)peer().parameters);
response << _gateway.createSession(_farId,peer(),requestKey,responseKey);
response.write8(0x81);
response.writeString8(_signature);
response.writeRaw((char*)pubKey,sizeof(pubKey));
response.write8(0x58);
// remove cookie
_cookies.erase(itCookie);
// db_add_public(s); // TODO
return 0x78;
}
default:
ERROR("Unkown handshake packet id '%02x'",id);
}
return 0;
}
